Grinding-roll and method of manufacturing the same



(No Model.) I

R. BIRKHOLZ. GRINDING ROLL AND METHOD OF MANUFACTURING THE SAME. No. 257,647.

Patented May 9, 1882.

phnr. Washinglon. n, c.

omen STATES PATENT OFFICE.

nionann BInKno z, o1? MILWAUKEE, WISCONSIN.

GRINDING-ROLL AND METHOD OF MANUFACTURING THE SAME.

SPECIFICATION forming part of Letters Patent No. 257,647, dated May 9, 1882.

ii Application filed February 20, 1882. (X0 model.) i

. To all whom it may concerni 1 Manufacturing the Same, of which the follow.

ing is a specification.

My invention relates to thatclass of grinding-rolls which are provided with cutting ribs; or teeth; and the main object of theinvention is to provide the same at afar less cost than usual. t

To this end the invention consists in easting the rolls with the teeth or ribs upon them in a chill, and subsequently removingthe edges of the teeth by submitting therolls to the action of a grinding-machine,whereby the edges of the ribs are brought to the proper condition for, use and at the same time rendered perfectly true.

The invention also consists in a new article of manufacture consisting of a cast metal grinding-roll having thereon chilled ribs or teeth having their extremities ground away, as and for the purpose set forth.

Hitherto it has been the almost universal practice to construct the roll with chilled faces, and after turning it to a true cylindrical form to form ribs or teeth thereon by means of cutting-machines. This operation was slow, la horious, and exceedinglyexpensive, rendering the cost of the rolls so great that they could be employed only in merchant-mills and by professional, millers. Moreover, the removal of the outer hardened surface by the cutting or grooving tools left the cutting-surfaces comparativeIy soft, so that they were rapidly worn away by use.

By my invention I am enabled to produce the rolls so cheaply that they may be purchasedand used by farmers and othersfor do mestic purposes, and to leave the cutting-surfaces of the rolls of extreme hardness, so that the rolls may be run for a much longer period of time than those ofthe ordinary construction. The fact that in the manufactureof my roll the grinding action exposes in the outer sur face of the tooth a small amount of the softer metal is also of advantage, it being found that the soft portion will wear gradually away, leaving the hardened edges sharp and true.

Referring to the accompanfving drawings,

Figures 1 and 2 represent respectively an end and side view of my roll as it appears upon leaving the chill or mold. Figs. 3 and 4 are similar views of the roll as it appears in its finished condition. Fig. 5, is a top plan View ofa sectional chill, Fig.6 is a vertical section through the central portion of the same. Fig.

7 is'a view of a chill made in one piece. Fig. .8 is a diagram illustrating themannerin which the rolls are ground andfinished.

In proceeding to construct a roll upon my plan I first provide a hollow cylindrical metal mold or chill, A, which may be made in one or more sections, and which is provided on the inner surface with ribs or teeth corresponding in form with those required upon the surface of the roll, except that in the chill the inner surface is preferably adapted to produce sharp outer edges on the teeth. The molten iron or other metal isfirstpoured into the mold, producing a roller-body having on its surface teeth or ribs which are chilled to a great hardness, and which present sharp outer edges, as represented in Figs. 1 and 2. The roller thus produced is next placed in an emery-grinder or grindingmachine of ordinaryeonstruction (represented in outline in Fig.8) and subjected to theaction ofan emery-wheel or other grinder, while be ing revolved upon its axis, in such manner as to grind away the extreme outer edges of the teeth or ribs and render them true and concentric with the axis of the roll, the result being such a roll as represented in Figs. 3 and 4. This roll,presentinga true and accurate outer surface or periphery, may be adjusted with the same degree of accurac Y and nicety in a mill as those manufactured in the ordinarymanner. The chilled surface of the teeth enables the roll to run fora greater length of time and remain sharp when in use.

I am aware that it is old to cast grindingrolls with ribs or teeth thereon, and this I do not claim.

I am also aware that it is old to grind smooth porcelain bodies or bodies of other material to give them a true cylindrical form; but I am not aware that any one has hitherto constructed a roll with a chilled surface by first casting the same with teeth thereon of greater length than required and subsequently grinding away the points of the teeth to complete the roll,and this I claim as myinvention without reference to the peculiar form of the teeth which may be employed.

Referring to Figs. 5 and 6, the chill consists of three sections, a, surrounded bya ring, I), and forced together by screw 0, the ring I) serving to sustain the screws and bind the parts together.

In order to chill the edges of the roll atthe ends, rings at are applied, as shown in both figures, and flask-rings e are also applied to the upper and lower ends of the body I), as shown. These rings are continuations of the flask or chill to retain the sand orother molding material, as usual.

In Fig. 7 the chill is shown as made complete in one piece.

Referring to the grinding apparatus shown in Fig. 8, B represents the body of the roll, mounted and arranged to revolve in suitable bearings, and provided at one end with a pulley, through which motion is received from a driving-belt to turn the roll upon its axis.

0 represents the grinding-wheel, of emery or equivalent material, mounted on a suitable arbor, and arranged to slide lengthwise with respect to the roll I), while receiving at the same time a rotary motion.

Having thus described my invention, what I claim is-- 1. Asan improvement in the art of manafacturinggrinding-rolls, the method consisting in first casting the roll in a chill with teeth or ribs thereon, and subsequently grinding away the points or edges of the teeth to complete the roll.

v2. As a new article of manufacture, a castmetal grinding-roll having thereon chilled ribs or teeth, portions of the edges of which are of softer metal than the remainder, as described and shown.

3. As a new article of manufacture, the castmetal roll having thereon and integral therewith the chilled teeth or ribs with ground points or extremities.

RICHARD BIRKHOLZ.-

Witnesses:

J. E. WILDISII, ELMORE CHENEY. 

